wpo - the sun & whitelight/spectrohelioscope coelostat

a single flat mirror piggybacked on an equatorially driven scope sends a beam of sunlight into a fixed telescope.

   solar system page

2000 Feb 20 :  Experiments conducted to see if the Meade LX200 could be used to send a beam of sunlight into the adjacent observatory annex to a fixed solar telescope [white-light] or future spectrohelioscope [SHS] to view the disk in monochromatic light like Ha.  It involved a series of plane mirrors [ex-Newtonian flats], two fixed [M2 & 3] with one [M1] riding piggy-back on the LX200 turning at 1 rev-per-day to track the sun.  M1 then directs sunlight up the polar axis [to M2] way from the telescope as a polar heliostat.
The project proved successful but was not followed -up and abandoned in Jan 2005 when a Coronado PST [H-alphascope] was acquired.

The potential aperture of the instrument would be a modest 30mm but continuing tests on the C8 stopped to this aperture [below] successfully show excellent images x80 - a higher magnification than would be applied to a SHS for example.  Using a slit, second lens plus 1200 lines/mm blazed grating [not shown] numerous lines in the sun's spectrum projected onto white card clearly visible in the darkened annex.  By substituting a sheet of white [developed] bromide paper or computer/ photocopy printer paper the H and K lines [CaII] in the far violet are clearly visible too.  These papers conveniently fluoresces to ~360nm i.e. well beyond normal human vision !